Ever wonder what happened to the singing Von Trapp family after they escaped the Nazis by climbing the Alps at the end of “The Sound of Music”?

Probably not, especially since in real life they simply boarded a train to Italy. But that hasn’t stopped the creators of “The Hills Are Alive!,” the new musical spoof/sequel being presented by the Fringe Festival. Unfortunately, what might have made for a funny “SNL” sketch is dragged out to two sluggish hours, with laughs coming few and far between.

Written by Frankie Johnson (book and lyrics) — who also directed and plays one of the children — and Eric Thomas Johnson (music), the show slavishly parodies the Rodgers and Hammerstein musical, especially the film version. It begins with an overture, and it isn’t long before we see Fraulein Mathilde — the name has been changed from Maria, the better to avoid legal issues — twirling maniacally on a mountaintop.

As with most parodies, the creators’ affection for their source material is evident. Most of the songs directly reference their inspirations, with “Edelweiss” replaced by the far darker “Wiegenlied” and “Something Good” turned into — what else? — “Something Bad.” But despite the composers’ undeniable skill for aping R&H’s operetta-style music, their score simply slows things down even more.

One of the more subversive jokes has the eldest son taking an unhealthy interest in his new stepmother. (“She’s wonderful . . . blond, soprano and just crazy enough to be interesting,” he gushes.) A few of the physical gags are mildly amusing, such as when one of the children is suddenly carried away by a “bear,” or when Maria — sorry, Mathilde — is seen falling off a cliff in the distance. And it’s hard not to smile when Captain van Klapp serenades his children on guitar while we only hear the sounds of a tinkling piano. But generally the humor is more sophomoric than witty.

The affectionately ragtag production — the mountains are represented by ladders draped with sheets — befits the Fringe, and the game cast goes through the paces with admirable energy. Daniele Hager is very funny as the perpetually ignored daughter Magda, and Ashley Ball skillfully mimics Julie Andrews’ refined vocal tones. But a silly musical like “The Sound of Music” deserves far more scathing satirical treatment than it receives here. Where are Matt Stone and Trey Parker when you need them?